Field
Embodiments of the disclosure generally relate to methods for in-situ dry cleaning a plasma processing chamber.
Description of the Related Art
Refractory metal and metal silicide are widely used in ultra-large scale integration (ULSI) circuits for gate structure and interconnect. To fabricate gate electrodes, the device must be dry etched at points in the manufacturing process. This includes interaction with bromine, fluorine and chlorine, among other harsh chemistries. After dry etching these materials, however, metal containing by-products and/or residues may gradually build up on the surfaces of the chamber components of the processing chamber which in turn affects the ability to maintain process control during circuit fabrication and therefore the subsequent process. Accumulation of such by-products or residues also becomes a source of unwanted particles that may contaminate the substrate. These metal containing by-products or residues cannot be effectively removed by conventional in-situ chamber clean process using fluorine or chlorine based plasma since they also produce non-volatile by-products which remain on the etched surface of the chamber components. The chamber clean process may require complicated and long process, which affects the process throughput.
Therefore, there is a need for an improved process for cleaning plasma processing chamber after etching of a substrate.